The node in a cladogram represents the formation of a new species. The formation of a new species is termed as a speciation event.The node in cladogram indicates the point at which a splitting event, or formation of a new species occurred.The line between two nodes is called the internode. It represents at least one hypothetical ancestor.A cladogram is a tree shaped diagram that is used to illustrate evolutionary relationships among species by analyzing some similarities or differences in physical features and other kinds of characters in the organisms.
The goal of a cladogram is to show relationships and evolutionary descent between species.
As many researchers hypothesize that the old single-celled organism or the origin of the complex-celled organisms came from the endosymbiosis of the mitochrondrion organism and the prokaryotic cell. It has been said that mitochondria was an independent organism which then to have been evovled itself after planting itself inside a prokaryotic cell which aided cellular respiration and production of ATP (Adenosine Triphosphate). This then aided the prokaryotic cell to be more sophisticated and caused another change from having without a true nucleus to a eukaryotic cell with a nucleus and embedded DNA.
